ionic bond:: coulombic attraction between an e- rich and e- poor atom

covalent bond:: sharing electrons between atoms

octet rule mainly applies to:: second row elements

octet rule:: atoms tend to gain or lose e- to obtain noble gas configuration (8 val e-)

BF3:: 6 val e-, very e- deficient

BF3 is:: very reactive with compounds that have LPE

PCl5 and SF5:: have over-filled val shell

bond line formula::

1. each line is a bond

2. each terminus is a carbon

3. each carbon follows octet rule (H fills octet unless otherwise stated)

4. atoms other than C and H are labeled

5. H attached to heteroatoms are explicitly written (OH, NH2, SH, etc)

formal charge:: #bonds + #LPE - val e- in neutral atom

balanced formal charge:: more stable than other versions of the same compound

resonance structures:: more than one possible lewis structure

resonance structures are really:: hybrid orbitals that exist in an inbetween form rather than multiple distinct resonance forms

possible resonance structures can be drawn as:: multiple structures or one structure with delocalized e-

resonance rules::

1. keep atomic positions the same

2. octet rule still applies

3. when there are multiple possible versions, the one with the least charge separation is the most stable

4. when 2+ atoms can support formal charge, the more EN atom is more stable with (-) charge

5. each resonance structure should have the same # e- and the same net charge

6. each resonance structure should have the same # LPE

7. electron delocalization stabilizes the structure

lewis structure cannot:: predict molecular geometry

VSEPR:: LPE will stay as far from each other as possible to minimize repulsion between them

lewis structure + VSEPR can:: predict molecular geometry

tetrahedral bond angle:: 109.5°

trigonal planar bond angle:: 120°

molecular orbital theory question:: why atoms need to come together in covalent bonds (why bonding releases energy)

LCAO derived from:: schrödinger’s equation and wave function

LCAO:: combining wave functions linearly to get a new wave function for the molecular orbital

rules of MO theory::

1. of MO generated from AO mixing = # AOs used to make MO

2. e- fill the MOs according to Aufbau, Pauli, and Hund

Aufbau :: orbitals filled from lowest to highest energy level

Pauli :: 2 e- per orbital and e-’s have opposite spins

hund:: single fill orbitals of equal energy before pairing e-

hybridization:: combining multiple individual wave functions to get a new wave function for a new orbital

sp orbital shape:: uneven dumbell

sp orbital can:: form sigma bonds with other s orbitals (bonding if same sign, antibonding if different)

bonding orbital:: effective overlap

antibonding orbital:: ineffective overlap

boron can:: promote a 2s e- to a 2p e-, creating 3 sp2 orbitals

finger trick:: count bonding e- pairs/LPE/areas of e- density on your fingers starting with thumb (s) then fingers (p, p2, p3)

sp3 hybridization structure:: tetrahedral

pi bond:: double bond, p orbital dumbells line up (either bonding or antibonding)

sigma bond:: single bond only

nodal plane:: goes between antibonding orbitals